The present invention relates to a new and distinct cultivar of Agastache, given the name, ‘Blue Boa’. Agastache is in the family Lamiaceae. This new variety is a selection out of a breeding line using Agastache rugosa as a parent to provide hardiness and wet soil tolerance. This seedling was selected for its deep purple blue color and good habit. The exact parents are unknown.
Compared to Agastache ‘Blue Fortune’ and ‘Black Adder’, both unpatented plants, the new cultivar has deeper purple blue flower color, wider flower spikes, and a shorter habit.
This plant exhibits the following characteristics that make it unique:                1. deep purple blue flower,        2. large inflorescences,        3. a long bloom time,        4. a stiffly upright, medium habit,        5. and excellent vigor.        
The new variety has been reproduced only by asexual propagation (stem cuttings and micropropagation using apical buds and nodes). Each of the progeny exhibits identical characteristics to the original plant. Asexual propagation by stem cuttings and micropropagation using apical buds and nodes as done in Canby, Oreg., shows that the foregoing characteristics and distinctions come true to form and are established and transmitted through succeeding propagations. The present invention has not been evaluated under all possible environmental conditions. The phenotype may vary with variations in environment without a change in the genotype of the plant.